1. Field of the Invention
This application is directed toward fire-rated wall construction components for use in building construction.
2. Description of the Related Art
Fire-rated wall construction components and assemblies are commonly used in the construction industry. These components and assemblies are aimed at preventing fire, heat, and smoke from leaving one portion of a building or room and entering another, usually through vents, joints in walls, or other openings. The components often incorporate the use of a fire-retardant material which substantially blocks the path of the fire, heat, and smoke for at least some period of time. Intumescent materials work well for this purpose, since they swell and char when exposed to flames, helping to create a barrier to the fire, heat, and smoke.
One example of a fire-rated wall construction component is the Firestik® head-of-wall fireblock product. The Firestik® head-of-wall fireblock incorporates a metal profile with a layer of intumescent material on its inner surface. The metal profile of the Firestik® head-of-wall fireblock is independently and rigidly attached to a wall component, such as the bottom of a floor or ceiling, and placed adjacent to other wall components, such as a stud and track. The intumescent material, which is adhered to the inner surface of the metal profile, faces the stud and track, and the space created in between the intumescent material and the stud and track allows for independent vertical movement of the stud in the track when no fire is present.
When temperatures rise, the intumescent material on the Firestik® head-of-wall fireblock expands rapidly. This expansion creates a barrier which encompasses, or surrounds the stud and track and substantially prevents fire, heat, and smoke from moving through the spaces around the stud and track and entering an adjacent room for at least some period of time.
While the Firestik® head-of-wall fireblock serves to prevent fire, heat, and smoke from moving through wall joint openings, it also requires independent attachment and proper spacing from wall components. It would be ideal to have wall components and systems which themselves already incorporate a fire-retardant material.
An additional problem regarding current fire-rated wall components concerns ventilation. Exterior soffits for balconies or walkways are required to be fire rated. However, these soffits need to be vented to prevent the framing members from rotting. The rot is caused when airflow is taken away and condensation forms inside the framing cavity. The moisture from the condensation attacks the framing members and destroys them from the inside out. In many cases, the deterioration is not noticed until the framing is completely destroyed. Therefore, a fire-rated wall component is needed which accommodates proper ventilation during times when no fire or elevated heat is present, and seals itself when fire or elevated heat is present.